1. Field of the Invention
This invention relates to a lens, more particularly to a lens that guides emission of light sideways.
2. Description of the Related Art
In U.S. Pat. No. 6,679,621, there is disclosed a conventional lens that serves to guide light emitted by a light source sideways. The conventional lens defines a central axis, and includes a bottom surface, a reflecting surface, and a refracting surface.
When the light source emits light, a portion of the light passes through the bottom surface, is incident on and is reflected by the reflecting surface to the refracting surface, and is refracted by the refracting surface such that the light exits the lens in lateral directions relative to the central axis. Moreover, another portion of the light passes through the bottom surface, and is refracted by the refracting surface such that the light exits the lens in lateral directions relative to the central axis.
The aforementioned conventional lens is disadvantageous in that, since the light reflected by the reflecting surface to the refracting surface forms an oblique angle with the refracting surface, a portion of the light is reflected by the refracting surface, thereby decreasing the efficiency of the light emitted through the lens by the light source.
In U.S. Pat. No. 6,607,286, there is disclosed another conventional side emitting lens. The conventional lens includes a sawtooth-shaped light exiting surface. This makes fabrication of the conventional lens relatively difficult.